The reverse shoulder prosthesis has been indicated for use in patients with a nonfunctioning rotator cuff, pain, secondary arthropathy, and pseudoparalysis. Patients receiving a reverse shoulder prosthesis implantation typically have muscle deficiencies which prevent them from achieving internal or external rotation or more complex motions which require either internal or external rotation in combination with another type of motion. One such example is a clinical symptom commonly referred to as the “Hornblower's sign” or “dropping sign”, a condition in which deficiencies in the external rotator muscles prevent the patient from externally rotating the arm as it is elevated and often result in the arm falling into internal rotation when the arm is elevated. External rotation is used for many activities of daily living, including, but not limited to, eating and brushing one's teeth. Some of the external rotators in the shoulder are the posterior deltoid, the infraspinatus, and the teres minor—patients with cuff tear arthropathy typically have little functional infraspinatus or teres minor.